Cryotubes are designed with your sample in mind - we want to make sure your sample is protected, accessible, and securely stored. The most important facet of this is the seal itself, the cap that separates your sample from the rest of the world. Oxford Lab Products Maxxline Cryotubes are engineered with a special sealing system based around the cap design. The threading on Maxxline Cryotubes is external, meaning that the internal space of the tube is further protected from contaminants. Furthermore, the cap creates a lip seal to prevent any leaks while the sample is in storage. Caps require only a half turn to create a tight seal; this also enables users to easily open the vial with one hand for improved usability.Beyond being safe and secure, Oxford Lab Products Maxxline Cryotubes are also designed to be convenient and durable. All of vials are sterilized and maintain that sterility for 5 years from the sterilization date. As further durability, Maxxline Cryotubes are made from a unique polypropylene formulation. This allows them to be safe for use over a large range of temperatures (-196°C to 121°C). These tubes can also withstand pressures as high as 95kPa. They can be autoclaved after use to again minimize the risk of sample cross-contamination. Finally, each vial is equipped with a conical bottom with a star-shaped foot underneath. This design allows samples to be accessed much more easily as there are no corners inside, but the foot still allows the tube to be self-standing for ease-of-use.Features:Colored Caps Accessible for Easy IdentificationExternal Threading and Quick-Seal Cap Prevent Leaks and ContaminationLarge Blank Space Allows for Easy LabelingDesigned to Fit into 10x10 and 9x9 Cryogenic Storage BoxesGraduation Markings at Every 0.5mLStar-Shaped Base Ensures Vial Stays Upright During Usage and StorageSterilized via ISO11137 Compliant ProcessFree of Heavy Metals, BSE/TSE, Cytotoxins, RNAses, and DNAsesAccessible in Double-Safety Self-Standing Bulk Bags or Eco-Friendly RacksHigh Pressure Tolerance (95kPa/0.95bar)QC tested and regulated to adhere to Oxford Lab Products standards.